Based on calculation and analysis of noise measurement results，this paper compared the average weighted equivalent continuous perceived noise level at noise sensitive sites around three different types of airports during one day and night，two consecutive days and nights，and seven consecutive days and nights. It was found that the biggest difference of the sound level between one day and night and seven consecutive days and nights was less than 2.2 dB for the same monitoring target，and less than 1.8 dB between two and seven consecutive days and nights. There was no significant difference of the monitoring results among the three monitoring frequencies for the same monitoring target.